1. Field of the Invention
The present invention relates to a heat processing device which performs a heat processing on a semiconductor substrate, a glass substrate for a liquid crystal display, a glass substrate for a photo-mask, a substrate for an optical disk, and the like (hereinafter, referred to as “substrate”).
2. Description of the Background Art
As a heat processing device for rapidly heating or cooling a substrate, a heat processing device as shown in FIG. 7 has been known (see Japanese Patent Application Laid-Open No. 2001-313328, for example).
FIG. 7 shows the configuration of a main part of a conventional heat processing device. A heat processing device 100 shown in FIG. 7 includes a holding table 101 employing a heat pipe structure HS so that its heat capacity is considerably reduced while the in-plane evenness of the temperature distribution is enhanced. A substrate W is mounted on a mounting face 101a corresponding to an upper surface thereof.
A cavity is formed inside the holding table 101. An inner space 102 thereof is depressurized due to the heat pipe structure HS, and a plurality of pillars 103 are erected so as to compensate for the strength thereof in the vertical direction.
A heater 105 is installed inside a working liquid room 104 in which working fluid 106 is stored. Moreover, the working liquid room 104 and the inner space 102 of the holding table 101 are communicated with each other. Therefore, steam of the working fluid 106, which is generated by heating the heater 105, is allowed to shift through the inner space 102 and transfer or receive latent heat of vaporization so that the mounting face 101a is heated rapidly with the temperature distribution of the mounting face 101a being kept evenly.
A cooling plate 107 is attached to a position that is interposed between two working fluid rooms 104. A flow passage, which is not shown, is formed inside the cooling plate 107, and a refrigerant is supplied into the flow passage through a supply pipe 108. After heat exchange has been performed inside the flow passage, the refrigerant is discharged from a discharging pipe 109 so that the holding table 101 is cooled rapidly.
However, upon cooling the holding table 101 by supplying the refrigerant to the cooling plate 107, depending on the heat capacity, the temperature conditions and the like of the refrigerant, the thermal transfer from the mounting face 101a to the cooling plate 107 through the pillars 103 becomes more influential than the function of the heat pipe structure HS for keeping the temperature distribution of the mounting face 101a evenly, resulting in unevenness in the temperature distribution of the mounting face 101a. Therefore, when temperature controls are performed through a heating processing using the heater 105 and a cooling processing using the cooling plate 107 so as to process a wafer with a substrate W being held on the holding table 101 of the heat processing device as disclosed in Japanese Patent Application Laid-Open No. 2001-313328, the temperature distribution on the substrate W becomes uneven, resulting in deterioration in the film-thickness evenness and the line-width evenness in a circuit pattern to be formed on the substrate W.